# Abyssal hydrothermal alteration drives the evolution from simple alkanes to prebiotic molecular complexity

## TL;DR

Deep-sea hydrothermal vents transform simple alkanes into complex organic molecules, offering insights into prebiotic chemistry and potential life markers on other celestial bodies.

## Contribution

A metabolomics-inspired strategy reveals a systematic molecular evolution pattern in hydrothermal vent chemistry.

## Key findings

- Organic molecules from different vent fields show shared molecular connection patterns.
- Molecular evolution progresses from alkanes to complex heteroatom-bearing compounds.
- Hydrothermal systems may have shaped life's essential feedstock on early Earth.

## Abstract

Abyssal hydrothermal vents are regarded as reactors for simple reduced carbon transforming into more complex forms of prebiotic organic chemistry. While the organic geochemical continuum and evolutionary transitions remain elusive, due to the intense hydrothermal alteration. We apply a metabolomics-inspired molecular fingerprinting strategy integrating mass spectral networking and hierarchical organization, to construct a molecular relatedness phylogenetic tree for vents from ultraslow-spreading Indian Ridge. Here we show that organic molecules from different vent fields and activity states share common molecular connection patterns. The observed progressive molecular evolution from alkanes through aromatics to complex heteroatom-bearing compounds reveals a systematic increase in molecular functionalization and polarity. This finding helps bridge the gap between simple reduced carbon and prebiotic molecular complexity, underscoring the role of hydrothermal systems in shaping life’s essential feedstock on the primordial Earth. This framework may contribute to the search for life-markers on other astrobiological contexts, e.g., Mars, Enceladus, Callisto and Europa.

Deep-sea hydrothermal vents drive the transformation of simple alkanes into complex organic molecules, revealing a universal pattern of molecular evolution that may inform the search for life’s origins on Earth and beyond.